Engineer Evan Long posted the video above (via Engadget) showing what is apparently an iPod touch equipped with a slightly modified Square credit card reader capable of playing back audio from an old reel-to-reel tape player:

The magnetic stripe reader on the Square basically works exactly like the magnetic read and write heads on an old school cassette player or reel-to-reel machine… Since the headphone jack on most iPods and the iPhone doubles as a microphone input (that’s how the Square reader transfers data) all you then need to do is fire up your favorite audio recording app, and find an easy way to thread the audio tape through.